Lease Obligations - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Finance leases, assets, gross	$ 638.6		$ 638.6		$ 563.0
Finance Lease, Liability, Statement of Financial Position [Extensible List]	Property and equipment, net		Property and equipment, net		Property and equipment, net
Finance leases, assets, net	$ 463.2		$ 463.2		$ 418.7
Finance leases, assets, depreciation	21.1	$ 17.5	58.8	$ 50.1
Operating leases, additions	3.9	3.3	89.2	16.6
Operating leases, expense	26.1	25.6	81.6	87.7
Operating leases, variable lease costs	2.4	2.3	7.5	8.0
Operating leases, short-term leases, expense	$ 158.3	$ 74.0	$ 399.2	$ 224.4
Finance leases, weighted average remaining lease term (in years)	2 years 6 months		2 years 6 months
Finance leases, weighted average discount rate, percent	3.40%		3.40%
Operating leases, weighted average remaining lease term (in years)	3 years 9 months 18 days		3 years 9 months 18 days
Operating leases, weighted average discount rate, percent	3.10%		3.10%
2021 Acquisitions
Lessee, Lease, Description [Line Items]
Operating leases, additions			$ 74.6
Minimum
Lessee, Lease, Description [Line Items]
Operating leases, term of contract (in years)	1 year		1 year
Minimum | Equipment Leases
Lessee, Lease, Description [Line Items]
Leases, renewal term			1 year
Minimum | Facility Leases
Lessee, Lease, Description [Line Items]
Leases, renewal term			1 year
Maximum
Lessee, Lease, Description [Line Items]
Leases, remaining lease terms			10 years
Operating leases, term of contract (in years)	1 year		1 year
Maximum | Equipment Leases
Lessee, Lease, Description [Line Items]
Leases, renewal term			5 years
Maximum | Facility Leases
Lessee, Lease, Description [Line Items]
Leases, renewal term			5 years